This is the conclusion of a series, and a lot of its emotional weight as well as its worldbuilding rests on having read the previous volumes. To use Jo Walton’s spearbuilding metaphor, this is a very sharp point on a very long spear. It’s sharp enough that even without the long spear, the point will probably cut skin easily, but with it, this book will go right through you and also impale your next-door neighbor.

At the beginning of the book, Jane and Vincent are ready to return to England when they find that Vincent’s brother needs them to go to Antigua on urgent family business. Vincent’s relationship with his relations, as readers of the previous books will know, have been strained at best, but some crises are important enough to encourage cooperation–especially with Vincent’s closest and least-fraught brother. When he gets there, he finds that the problems are not only at the core of his family but also with the conditions of the estate, its managers, and the slaves who have lived upon it. Jane is plausibly–and appropriately for the particular period–a mild abolitionist: not a modern person in a period dress, but someone who is horrified by the institutions of slavery–and yet still has some assumptions to unlearn about race herself.

In the midst of all of this, Jane finds herself pregnant with a much-wanted child who complicates matters immensely: it is widely believed that working glamour (magic) can cause miscarriages. This is an interesting case of something we don’t see enough of in fantasy: a place where different characters believe that magic works different ways, so that the exposition of the protagonist’s beliefs are important without being a definitive statement of ultimate truth. The slaves with whom Jane interacts have completely different assumptions about magic and how it is and should be done, and her attempts to learn from them feel very frustratingly realistic–and so do her frustrations with her own limitations.

The entire structure of the book hands Jane and Vincent one hard choice after another, regarding magic, human rights, and family. It’s no shame, then, that the true climax of the book is not quite so fraught. Some of the plot twists struck me as a bit obvious, but this is not a book whose power relies upon shock value. Rather, it’s focused on the emotional core of two people who love each other very much (and who are better at loving each other than they were for the first book), and how they face difficulties together. If you have someone close to you who has been through abuse–if you are that person yourself–this book may be difficult in spots, but it is incredibly well done. You may want to choose a moment when you’re feeling strong and supported to read it, but I don’t think it’s one you’ll want to miss.